The objective of this research is to isolate and characterize the protein fractions of brain proteoglycans. The results obtained will help to understand the structure of these proteoglycans and may give an insight into their biological role. Binding studies of brain proteoglycans and their proteins to hyaluronic acid will be used to determine the macromolecular structure of these aggregates in brain tissue. Due to the close proximity of brain proteoglycans to cell membranes, the possible mode of interaction will be studied utilizing well defined synthetic model membrane systems with the isolated proteoglycans and their protein constituents.